Precious metal recovery from electronic waste by a porous porphyrin polymer
Precious metal recovery from electronic waste by a porous porphyrin polymer
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DOI：
10.1073/pnas.2000606117
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发表时间：
2020-07-14
影响因子：
11.1
通讯作者：
Yavuz, Cafer T.
中科院分区：
文献类型：
--
作者：
Hong, Yeongran;Thirion, Damien;Yavuz, Cafer T.
从印刷电路板（PCB）等电子废物中提取贵金属的城市开采尚不可行，因为隔离过程漫长，存在健康风险和环境影响。虽然多孔聚合物对捕获金属污染物特别有效，但具有卟啉连接体的那些聚合物尽管具有潜力，但尚未被考虑用于贵金属回收。在这里，我们报告了一种多孔卟啉聚合物，即使在存在元素周期表中的63种元素的情况下，也能从PCB浸出液中定量捕获贵金属。该纳米多孔聚合物由广泛可用的单体分两步合成而不需要昂贵的催化剂，并且可以在不损失活性的情况下按比例放大。通过还原捕获机制，金的回收率是理论极限的10倍，达到创纪录的1.62 g/g。在前30分钟内发生99%的吸收，吸附到多孔聚合物上的金属可以快速解吸并重复使用。密度泛函理论（DFT）的计算表明，积极有利的多核金结合增强吸附簇，导致快速捕获，而铂捕获主要保持在单一卟啉网站。
Urban mining of precious metals from electronic waste, such as printed circuit boards (PCB), is not yet feasible because of the lengthy isolation process, health risks, and environmental impact. Although porous polymers are particularly effective toward the capture of metal contaminants, those with porphyrin linkers have not yet been considered for precious metal recovery, despite their potential. Here, we report a porous porphyrin polymer that captures precious metals quantitatively from PCB leachate even in the presence of 63 elements from the Periodic Table. The nanoporous polymer is synthesized in two steps from widely available monomers without the need for costly catalysts and can be scaled up without loss of activity. Through a reductive capture mechanism, gold is recovered with 10 times the theoretical limit, reaching a record 1.62 g/g. With 99% uptake taking place in the first 30 min, the metal adsorbed to the porous polymer can be desorbed rapidly and reused for repetitive batches. Density functional theory (DFT) calculations indicate that energetically favorable multinuclear-Au binding enhances adsorption as clusters, leading to rapid capture, while Pt capture remains pre-dominantly at single porphyrin sites.